U.S. patent number 10,011,740 [Application Number 15/025,081] was granted by the patent office on 2018-07-03 for rosin esters and compositions thereof.
This patent grant is currently assigned to Kraton Chemical, LLC. The grantee listed for this patent is ARIZONA CHEMICAL COMPANY, LLC. Invention is credited to Marc de Pater, Harry Jerrold Miller, Lloyd A Nelson, Lien Phun, Paul A Williams.
United States Patent |
10,011,740 |
Nelson , et al. |
July 3, 2018 |
Rosin esters and compositions thereof
Abstract
Rosin esters are provided. The rosin esters can exhibit improved
color (e.g., the rosin ester can have a neat Gardner color of 4 or
less), improved oxidative stability (e.g., when 1000 ppm or less of
an antioxidant is present in combination with the rosin ester, the
rosin ester can exhibit an oxidative-induction time at 130.degree.
C. of at least 30 minutes), improved color stability (e.g., the
rosin ester can retain a neat Gardner color of 5 or less when
heated to a temperature of 160.degree. C. for a period of three
hours), or combinations thereof. Also provided polymeric
compositions comprising the rosin esters, as well as methods of
making the rosin esters.
Inventors: |
Nelson; Lloyd A (Savannah,
GA), Williams; Paul A (Savannah, GA), Miller; Harry
Jerrold (Savannah, GA), de Pater; Marc (Houton,
NL), Phun; Lien (Port Wentworth, GA) |
Applicant: |
Name |
City |
State |
Country |
Type |
ARIZONA CHEMICAL COMPANY, LLC |
Jacksonville |
FL |
US |
|
|
Assignee: |
Kraton Chemical, LLC
(Jacksonville, FL)
|
Family
ID: |
51842774 |
Appl.
No.: |
15/025,081 |
Filed: |
September 26, 2014 |
PCT
Filed: |
September 26, 2014 |
PCT No.: |
PCT/US2014/057674 |
371(c)(1),(2),(4) Date: |
March 25, 2016 |
PCT
Pub. No.: |
WO2015/048415 |
PCT
Pub. Date: |
April 02, 2015 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20160264821 A1 |
Sep 15, 2016 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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61883725 |
Sep 27, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C09D
193/04 (20130101); C09F 1/04 (20130101); C08L
93/04 (20130101); C08L 91/06 (20130101); C08L
23/0853 (20130101); C09J 193/04 (20130101); C08L
93/04 (20130101); C08L 53/00 (20130101); C08L
93/04 (20130101); C08L 23/0853 (20130101); C08L
93/04 (20130101); C08L 23/0853 (20130101); C08L
91/06 (20130101); C09J 193/04 (20130101); C08L
23/0853 (20130101); C09J 193/04 (20130101); C08L
23/0853 (20130101); C08L 91/06 (20130101) |
Current International
Class: |
C08L
93/04 (20060101); C09F 1/04 (20060101); C09J
193/04 (20060101); C09D 193/04 (20060101) |
Field of
Search: |
;524/271 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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103002321 |
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Apr 2011 |
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CN |
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2824154 |
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Jan 2015 |
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EP |
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7-11194 |
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Jan 1995 |
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JP |
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2009-84421 |
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Apr 2009 |
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JP |
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2009084421 |
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Apr 2009 |
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JP |
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2009-161573 |
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Jul 2009 |
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JP |
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2013/133407 |
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Sep 2013 |
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WO |
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Other References
International Search Report and Written Opinion dated Jun. 2, 2015,
as issued in PCT Application No. PCT/US2014/057685 filed Sep. 26,
2014. cited by applicant .
International Search Report and Written Opinion dated Jun. 2, 2015,
as issued in PCT Application No. PCT/US2014/057691 filed Sep. 26,
2014. cited by applicant .
CABOT: "Norit AZO", Cabot Technical Data Sheets, Jul. 17, 2007,
XP002735930. cited by applicant.
|
Primary Examiner: Chin; Hui
Attorney, Agent or Firm: Page; Samantha Cantor Colburn
LLP
Claims
What is claimed is:
1. A rosin ester comprising at least 70% by weight of an esterified
dehydroabietic acid and an esterified dihydroabietic acid, wherein
the weight ratio of the esterified dehydroabietic acid to the
esterified dihydroabietic acid ranges from 1.3:1 to 1:2.6, wherein
the rosin ester has a weight average molecular weight of at least
800 g/mol as determined using gel permeation chromatography as
described in ATSM D5296-05.
2. The rosin ester of claim 1, wherein the rosin ester is derived
from tall oil rosin, gum rosin, wood rosin, or a combination
thereof.
3. A composition comprising (a) a polymer derived from one or more
ethylenically-unsaturated monomers, or a blend of two or more
polymers derived from one or more ethylenically-unsaturated
monomers, and (b) a rosin ester defined by claim 1.
4. A method of making a rosin ester comprising: (a) esterifying a
rosin with an alcohol to provide a crude rosin ester, and (b)
hydrogenating the crude rosin ester to form the rosin ester,
wherein the rosin ester has a weight average molecular weight of at
least 800 g/mol as determined using gel permeation chromatography
as described in ATSM D5296-05.
5. A composition comprising (a) 45% by weight to 75% by weight of
an oil, and (b) 25% by weight to 55% by weight of a rosin ester
defined by claim 1.
6. A composition comprising a rosin ester, the rosin ester
comprising at least 70% by weight of an esterified dehydroabietic
acid and an esterified dihydroabietic acid, wherein the weight
ratio of the esterified dehydroabietic acid to the esterified
dihydroabietic acid ranges from 1.3:1 to 1:2.6 and wherein the
rosin ester has a weight average molecular weight of at least 800
g/mol as determined using gel permeation chromatography as
described in ATSM D5296-05.
Description
TECHNICAL FIELD
This application relates generally to rosin esters, as well as
methods of making and using thereof.
BACKGROUND
Rosin esters, including rosin esters derived from polyhydric
alcohols, have been known for more than 50 years. See, for example,
U.S. Pat. No. 1,820,265 to Bent, et al. Rosin esters are typically
formed by the reaction of rosin. Which is primarily a mixture of
isomeric C.sub.20 tricyclic mono-carboxylic acids known as rosin
acids, with alcohols such as glycerol or pentaerythritol. The
resultant rosin esters serve as additives in a variety of
applications, including as tackifiers in hot-melt and
pressure-sensitive adhesives, modifiers for rubbers and various
plastics, emulsifiers for synthetic rubbers, base materials for
chewing gum, resins in coating compositions such as traffic paints
and inks, and sizing agents for paper making.
While suitable for many applications, many existing rosin esters
fail to possess suitable properties for particular applications.
Notably, many commercially available rosin esters are colored
(e.g., yellow or yellowish brown) and exhibit poor stability.
Accordingly, there continues to be a need for rosin esters which
exhibit improved color (e.g., are colorless or nearly colorless)
and improved stability.
SUMMARY
Provided herein are rosin esters that include at least 70% by
weight of an esterified dehydroabietic acid and an esterified
dihydroabietic acid. The weight ratio of the esterified
dehydroabietic acid to the esterified dihydroabietic acid in the
rosin ester can range from 1.3:1 to 1:2.6 (e.g., from 1.3:1 to
1:2.5, from 1.3:1 to 1:1.6, or from 1.2:1 to 1:1.5). The rosin
esters can be derived from tall oil rosin, gum rosin, wood rosin,
or a combination thereof. In some cases, the rosin ester is also
derived from a polyhydric alcohol, such as a polyhydric alcohol
selected from the group consisting of ethylene glycol, propylene
glycol, diethylene glycol, triethylene glycol, tetraethylene
glycol, trimethylene glycol, glycerol, trimethylolpropane,
trimethylolethane, pentaerythritol, mannitol, and combinations
thereof.
The rosin esters can be colorless or nearly colorless. For example,
the rosin ester can have a neat Gardner color of 4 or less (e.g.,
1.5 or less, or 1 or less). The rosin esters can have improved
color stability (e.g., the rosin ester can retain a neat Gardner
color of 5 or less when heated to a temperature of 160.degree. C.
for a period of three hours). The rosin esters can also exhibit
improved oxidative stability (e.g., when 1000 ppm or less of an
antioxidant is present in combination with the rosin ester, the
rosin ester can exhibit an oxidative-induction time at 130.degree.
C. of at least 30 minutes).
Also provided are polymeric compositions comprising a polymer
derived from one or more ethylenically-unsaturated monomers, or a
blend of two or more such polymers, and a rosin ester. The polymer
can be a homopolymer or a copolymer (e.g., a random copolymer or a
block copolymer) derived from one or more ethylenically-unsaturated
monomers, such as (meth)acrylate monomers, vinyl aromatic monomers
(e.g., styrene), vinyl esters of carboxylic acids,
(meth)acrylonitriles, vinyl halides, vinyl ethers,
(meth)acrylamides and (meth)acrylamide derivatives, ethylenically
unsaturated aliphatic monomers (e.g., ethylene, butylene,
butadiene), and combinations thereof. In some embodiments, the
rosin ester includes more than one type of rosin ester.
In some embodiments, the polymer derived from one or more
ethylenically-unsaturated monomers comprises a copolymer of
ethylene and n-butyl acrylate. In some embodiments, the polymer
derived from one or more ethylenically-unsaturated monomers
comprises a copolymer of styrene and one or more of isoprene and
butadiene. In certain embodiments, the polymer derived from one or
more ethylenically-unsaturated monomers comprises a polymer derived
from vinyl acetate. Polymers derived from vinyl acetate include
polymers derived, at least in part, from polymerization of vinyl
acetate monomers. For example, the polymer derived from vinyl
acetate can be a homopolymer of vinyl acetate (i.e., polyvinyl
acetate; PVA). The polymer derived from vinyl acetate can also be a
copolymer of vinyl acetate and one or more additional
ethylenically-unsaturated monomers (e.g., poly(ethylene-co-vinyl
acetate), EVA). In certain embodiments, the composition is a
hot-melt adhesive, such as an EVA-based hot-melt adhesive.
In some embodiments, the polymer is present in the composition in
an amount ranging from 20% to 60% by weight, based on the total
weight of the composition (e.g., from 30% to 40% by weight). In
some embodiments, the rosin ester is present in the composition in
an amount ranging from 20% to 50% by weight, based on the total
weight of the composition from 30% to 40% by weight). In certain
embodiments, the weight ratio of the polymer to the total amount of
esterified dehydroabietic acid and esterified dihydroabietic acid
in the composition is from 1:2.2 to 4.3:1 (e.g., from 1:1.1 to
2:1).
The polymeric compositions can exhibit improved thermal stability,
including improved viscosity stability on aging at elevated
temperatures (thermal aging), improved color stability on thermal
aging, or combinations thereof. For example, in some embodiments,
the composition exhibits a change in viscosity of less than 5% when
heated to a temperature of 177.degree. C. for a period of 96 hours.
In some cases, the composition exhibits a change of 5 or less
Gardner color units when heated to a temperature of 177.degree. C.
for a period of 96 hours.
Also provided are methods of making rosin esters. Methods of making
rosin esters can comprise (a) esterifying as rosin with an alcohol
to provide a crude rosin ester, and (b) hydrogenating the crude
rosin ester to form the rosin ester.
Esterification step (a) can comprise contacting a rosin with a
suitable alcohol under suitable conditions to provide the crude
rosin ester. The rosin can be selected from the group consisting of
tall oil rosins, gum rosins, wood rosins, or combinations thereof.
In some embodiments, the alcohol comprises a polyhydric alcohol,
such as ethylene glycol, propylene glycol, diethylene glycol,
triethylene glycol, tetraethylene glycol, trimethylene glycol,
glycerol, trimethylolpropane, trimethylolethane, pentaerythritol,
dipentaerythritol, mannitol, and combinations thereof.
Hydrogenation step (b) can comprise contacting the crude rosin
ester with a hydrogenation catalyst. Step (b) can be performed at
an elevated temperature, an elevated pressure, or combinations
thereof.
Optionally, a solvent can be present in esterification step (a),
hydrogenation step (b), or combinations thereof. In certain
embodiments, the rosin esterified in step (a) and/or the crude
rosin ester hydrogenated in step (b) comprise less than 25% by
weight solvent. In some embodiments, the concentration of
esterified rosin acids in the crude rosin ester hydrogenated in
step (b) is 75% or more by weight, based on the total weight of the
crude rosin ester. In some embodiments, the crude rosin ester is
substantially free of solvent (e.g., the crude rosin ester
comprises less than 1% by weight solvent, based on the total weight
of the crude rosin ester). In certain embodiments, the crude rosin
ester hydrogenated in step (b) has a viscosity of 1,000 cP or less
at 25.degree. C.
In some embodiments, the crude rosin ester obtained from
esterification step (a) is hydrogenated in step (b) without an
intervening distillation step. In certain embodiments, the crude
rosin ester obtained from esterification step (a) is hydrogenated
in step (b) without any intervening purification step.
In some cases, methods of making the rosin esters described herein
include only a single hydrogenation step. In some embodiments,
methods of making the rosin esters described herein consist
essentially of esterifying step (a) and hydrogenating step (b). In
certain embodiments, methods of making the rosin esters described
herein consist of esterifying step (a) and hydrogenating step
(b).
In certain embodiments, methods of making rosin esters can further
comprise disproportionating the rosin prior to the esterifying step
(a). The step of disproportionating the rosin can comprise
contacting the rosin with a disproportionation catalyst, such as a
phenol sulfide-type disproportionation catalyst.
DETAILED DESCRIPTION
Provided herein are rosin esters. The rosin esters can exhibit
improved color (e.g., the rosin ester can have a neat Gardner color
of 4 or less), improved oxidative stability (e.g., when 1000 ppm or
less of an antioxidant is present in combination with the rosin
ester, the rosin ester can exhibit an oxidative-induction time at
130.degree. C. of at least 30 minutes), improved color stability
(e.g., the rosin ester can retain a neat Gardner color of 5 or less
when heated to a temperature of 160.degree. C. for a period of
three hours), or combinations thereof.
Rosin esters can be formed by the esterification of rosin. Rosin,
also called colophony or Greek pitch (Pix gr ca), is a solid
hydrocarbon secretion of plants, typically of conifers such as
pines (e.g., Pinus palustris and Pinus caribaea). Rosin can include
a mixture of rosin acids, with the precise composition of the rosin
varying depending in part on the plant species. Rosin acids are
C.sub.20 fused-ring monocarboxylic acids with a nucleus of three
fused six-carbon rings containing double bonds that vary in number
and location. Examples of rosin acids include abietic acid,
neoabietic acid, dehydroabietic acid, dihydroabietic acid, pimaric
acid, levopimaric acid, sandaracopimaric acid, isopimaric acid, and
palustric acid. Natural rosin typically consists of a mixture of
seven or eight resin acids, in combination with minor amounts of
other components.
Rosin is commercially available, and can be obtained from pine
trees by distillation of oleoresin (gum rosin being the residue of
distillation), by extraction of pine stumps (wood rosin) or by
fractionation of tall oil (tall oil rosin). Any type of rosin can
be used to prepare the rosin esters described herein, including
tall oil rosin, gum rosin and wood rosin and mixtures thereof. In
certain embodiments, the rosin ester is derived from tall oil
rosin. Examples of commercially available rosins include tall oil
rosins such as SYLVAROS.RTM. 90, commercially available from
Arizona Chemical.
As described above, rosin includes a mixture of rosin acids (e.g.,
abietadienoic acids) which can include conjugated double bonds
within their ring systems. These conjugated double bonds can be a
source of oxidative instability. Accordingly, in some cases, the
rosin, rosin ester, or combinations thereof are processed to
decrease the weight percent of components which include conjugated
double bonds. For example, the PAN number of rosin or a rosin ester
refers to the weight percentage of abietadienoic acids (in
particular palustric, abietic and neoabietic acids) present in the
rosin or rosin ester, based on the total weight of the rosin or
rosin ester. The term "PAN number", as used herein, specifically
refers to the sum of the weight percentages of palustric, abietic
and neoabietic acid moieties in a rosin or rosin ester, as
determined according to method described in ASTM D5974-00
(2010).
The rosin ester can have a low PAN number. In some embodiments, the
rosin ester can have a PAN number, as determined according to the
method described in ASTM D5974-00 (2010), of 15.0 or less (e.g.,
14.5 or less, 14.0 or less, 13.5 or less, 13.0 or less, 12.5 or
less, 12.0 or less, 11.5 or less, 11.0 or less, 10.5 or less, 10.0
or less, 9.5 or less, 9.0 or less, 8.5 or less, 8.0 or less, 7.5 or
less, 7.0 or less, 6.5 or less, 6.0 or less, 5.5 or less, 5.0 or
less, 4.5 or less, 4.0 or less, 3.5 or less, 3.0 or less, 2.5 or
less, 2.0 or less, 1.5 or less, or 1.0 or less).
The rosin ester can comprise at least 70% by weight of an
esterified dehydroabietic acid and an esterified dihydroabietic
acid, based on the total weight of the rosin ester (e.g., at least
75% by weight of an esterified dehydroabietic acid and an
esterified dihydroabietic acid, at least 80% by weight of an
esterified dehydroabietic acid and an esterified dihydroabietic
acid, at least 85% by weight of an esterified dehydroabietic acid
and an esterified dihydroabietic acid, at least 90% by weight of an
esterified dehydroabietic acid and an esterified dihydroabietic
acid, or at least 95% by weight of an esterified dehydroabietic
acid and an esterified dihydroabietic acid).
In some embodiments, the weight ratio of esterified dehydroabietic
acid to esterified. dihydroabietic acid in the rosin ester is 1.3:1
or less (e.g., 1.25:1 or less, 1.2:1 or less, 1.15:1 or less, 1.1:1
or less, 1.05:1 or less, 1:1 or less, 1:1.05 or less, 1:1.1 or
less, 1:1.15 or less, 1:1.2 or less, 1:1.25 or less, 1:1.3 or less,
1:1.35 or less, 1:1.4 or less, 1:1.45 or less, 1:1.5 or less,
1:1.55 or less, 1:1.6 or less, 1:1.65 or less, 1:1.7 or less,
1:1.75 or less, 1:1.8 or less, 1:1.85 or less, 1:1.9 or less,
1:1.95 or less, 1:2 or less, 1:2.05 or less, 1:2.1 or less, 1:2.15
or less, 1:2.2 or less, 1:2.25 or less, 1:2.3 or less, 1:2.35 or
less, 1:2.4 or less; 1:2.45 or less, 1:2.5 or less, or 1:2.55). In
some embodiments, the weight ratio of esterified dehydroabietic
acid to esterified dihydroabietic acid in the rosin ester is at
least 1:2.6 (e.g., at least 1:2.55, at least 1:2.5, at least
1:2.45, at least 1:2.4, at least 1:2.35, at least 1:2.3, at least
1:2.25, at least 1:2.2, at least 1:2.15, at least 1:2.1, at least
1:2.05, at least 1:2, at least 1:1.95, at least 1:1.9, at least
1:4.85, at least 1:1.8, at least 1:1.75, at least 1:1.7, at least
1:1.65, at least 1:1.6, at least 1:1.55, at least 1:1.5, at least
1:1.45, at least 1:1.4, at least 1:1.35, at least 1:1.3, at least
1:1.25, at least 1:1.2, at least 1:1.15, at least 1:1, at least
1:1.05, at least 1:1, at least 1.05:1, at least 1.1:1, at least
1.15:1, at least 1.2:1, or at least 1.25:1).
The weight ratio of esterified dehydroabietic acid to esterified
dihydroabietic acid in the rosin ester can range from any of the
minimum values described above to any of the maximum values
described above. For example, the weight ratio of esterified
dehydroabietic acid to esterified dihydroabietic acid in the rosin
ester can range from 1.3:1 to 1:2.6 (e.g., from 1.3:1 to 1:2.5,
from 1.3:1 to 1:1.6, or from 1.2:1 to 1:1.5).
The rosin ester can be derived from any suitable alcohol, include
monoalcohols, diols, and other polyols. Examples of suitable
alcohols include glycerol, pentaerythritol, dipentaerythritol,
ethylene glycol, diethylene glycol, triethylene glycol, sorbitol,
neopentylglycol, trimethylolpropane, methanol, ethanol, propanol,
butanol, amyl alcohol, 2-ethyl hexanol, diglycerol,
tripentaerythritol, C.sub.8-C.sub.11 branched or unbranched alkyl
alcohols, and C.sub.7-C.sub.16 branched or unbranched
arylalkylalcohols. In certain embodiments, the rosin ester is
derived from a polyhydric alcohol. In certain embodiments, the
polyhydric alcohol can be selected from the group consisting of
ethylene glycol, propylene glycol, diethylene glycol, triethylene
glycol, tetraethylene glycol, trimethylene glycol, glycerol,
trimethylolpropane, trimethylolethane, pentaerythritol,
dipentaerythritol, mannitol, and combinations thereof.
The rosin ester can have a weight average molecular weight, as
determined using gel permeation chromatography (GPC) as described
in ASTM D5296-05, of at least 800 g/mol (e.g., at least 850 g/mol,
at least 900 g/mol, at least 950 g/mol, at least 1000 g/mol, at
least 1050 g/mol, at least 1100 g/mol, at least 1150 g/mol, at
least 1200 g/mol, at least 1250 g/mol, at least 1300 g/mol, at
least 1350 g/mol, at least 1400 g/mol, at least 1450 g/mol, at
least 1500 g/mol, at least 1550 g/mol, at least 1600 g/mol, at
least 1650 g/mol, at least 1700 g/mol, at least 1750 g/mol, at
least 1800 g/mol, at least 1850 g/mol, at least 1900 g/mol, or at
least 1950 g/mol). The blend of rosin esters can have a weight
average molecular weight of 2000 g/mol or less (e.g., 1950 g/mol or
less, 1900 g/mol or less, 1850 g/mol or less, 1800 g/mol or less,
1750 g/mol or less, 1700 g/mol or less, 1650 g/mol or less, 1600
g/mol or less, 1550 g/mol or less, 1500 g/mol or less, 1450 g/mol
or less, 1400 g/mol or less, 1350 g/mol or less, 1300 g/mol or
less, 1250 g/mol or less, 1200 g/mol or less, 1150 g/mol or less,
1100 g/mol or less, 1050 g/mol or less, 1000 g/mol or less, 950
g/mol or less, 900 g/mol or less, or 850 g/mol or less).
The rosin ester can have a weight average molecular weight ranging
from any of the minimum values above to any of the maximum values
above. For example, the rosin ester can have a weight average
molecular weight of from 800 g/mol to 2000 g/mol (e.g., from 900
g/mol to 1600 g/mol, or from 1000 g/mol to 1500 g/mol).
The rosin esters can have a low neat Gardner color. In some
embodiments, the rosin ester has a neat Gardner color, as
determined according to the method described in ASTM D1544-04
(2010), of 4.0 or less (e.g., 3.5 or less, 3.0 or less, 2.5 or
less, 2.0 or less, 1.5 or less, 1.0 or less, or 0.5 or less).
In certain embodiments, the rosin esters can exhibit improved color
stability. For example, the ester can retain a neat Gardner color
of 5 or less (e.g., 4.5 or less, 4.0 or less, 3.5 or less, 3.0 or
less, 2.5 or less, 2.0 or less, 1.5 or less, 1.0 or less, or 0.5 or
less) when heated to a temperature of 160.degree. C. for a period
of three hours.
The rosin esters can also exhibit improved oxidative stability. For
example, in some embodiments, when 1000 ppm or less of an
antioxidant is present in combination with the rosin ester, the
rosin ester can exhibit an oxidative-induction time at 130.degree.
C., as measured using the methods specified in ASTM D5483-05(2010),
of at least 30 minutes (e.g., at least 31 minutes, at least 32
minutes, at least 33 minutes, at least 34 minutes, at least 35
minutes, at least 36 minutes, at least 37 minutes, at least 38
minutes, at least 39 minutes, at least 40 minutes, at least 41
minutes, at least 42 minutes, at least 43 minutes, at least 44
minutes, at least 45 minutes, at least 50 minutes, at least 55
minutes, at least 60 minutes, at least 65 minutes, at least 70
minutes, at least 75 minutes, or longer). For example, when the
rosin ester includes 1000 ppm of antioxidant, or when the rosin
ester includes less than 1000 ppm of antioxidant (e.g., 800 ppm of
antioxidant, 600 ppm of antioxidant, 400 ppm of antioxidant, 200
ppm of antioxidant, 100 ppm of antioxidant, 50 ppm of antioxidant,
or 0 ppm of antioxidant), the rosin ester can exhibit the
oxidative-induction times described above at 130.degree. C., as
measured using the methods specified in ASTM D5483-05(2010). In
some cases, when 1000 ppm or less of an antioxidant is present in
combination with the rosin ester, the rosin ester can exhibit an
oxidative-induction time at 130.degree. C., as measured using the
methods specified in ASTM D5483-05(2010), of 250 minutes or less
(e.g., 200 minutes or less).
Optionally, the rosin esters can have a low hydroxyl number. In
some embodiments, the rosin ester has a hydroxyl number, as
measured using a modified version of the standard method provided
in DIN 53240-2 (different solvent tetrahydrofuran was applied), of
5.0 or less (e.g., 4.5 or less, 4.0 or less, 3.5 or less, 3.0 or
less, 2.5 or less, 2.0 or less, 1.5 or less, or 1.0 or less). The
hydroxyl number is expressed as mg KOH per gram rosin ester
sample.
The rosin ester can have a low acid number. In some embodiments,
the rosin ester has an acid number, as determined according to the
method described in ASTM D465-05 (2010), of 10.0 or less (e.g., 9.5
or less, 9.0 or less, 8.5 or less, 8.0 or less, 7.5 or less, 7.0 or
less, 6.5 or less, 6.0 or less, 5.5 or less, 5.0 or less, 4.5 or
less, 4.0 or less, 3.5 or less, 3.0 or less, 2.5 or less, 2.0 or
less, 1.5 or less, or 1.0 or less). The acid number is expressed as
mg KOH per gram rosin ester sample.
The rosin ester can optionally have low sulfur content. Sulfur
content can be measured with an ANTEK.RTM. 9000 sulfur analyzer
using the standard methods described in ASTM D5453-05. In some
embodiments, the rosin ester comprises less than 400 ppm sulfur
(e.g., less than 350 ppm sulfur, less than 300 ppm sulfur, less
than 250 ppm sulfur, or less than 200 ppm sulfur).
Also provided are polymeric compositions comprising a rosin ester
described herein and a polymer derived from one or more
ethylenically-unsaturated monomers. In this context, a polymer
derived from an ethylenically-unsaturated monomer includes polymers
derived, at least in part, from polymerization of the
ethylenically-unsaturated monomer. For example, a polymer derived
from an ethylenically-unsaturated monomers can be obtained by, for
example, radical polymerization of a monomer mixture comprising the
ethylenically-unsaturated monomer. A polymer derived from an
ethylenically-unsaturated monomer can be said to contain monomer
units obtained by polymerization (e.g., radical polymerization) of
the ethylenically-unsaturated monomer. Polymeric compositions can
also comprise a rosin ester described herein and a blend of two or
more polymers derived from one or more ethylenically-unsaturated
monomers. In these cases, the blend of two or more polymers can be,
for example, a blend of two or more polymers having different
chemical compositions (e.g., a blend of poly(ethylene-co-vinyl
acetate) and polyvinyl acetate; or a blend of two
poly(ethylene-co-vinyl acetates) derived from different weight
percents of ethylene and vinyl acetate monomers).
In some embodiments, the rosin ester includes more than one type of
rosin ester. For example, the rosin ester can include a mixture of
two rosin esters which are derived from the same type of rosin and
two different alcohols (e.g., a pentaerythritol ester of tall oil
rosin and a glycerol ester of tall oil rosin), a mixture of two
rosin esters which are derived from the same alcohol and two
different types of rosin (e.g., a pentaerythritol ester of tall oil
rosin and a pentaerythritol ester of gum rosin), or a mixture of
two rosin esters which are derived from two different alcohols and
two different types of rosin (e.g., a pentaerythritol ester of tall
oil rosin and a glycerol ester of gum rosin).
The polymer can be a homopolymer or a copolymer (e.g., a random
copolymer or a block copolymer) derived from one or more
ethylenically-unsaturated monomers. In other words, the homopolymer
or copolymer can include monomer units of one or more
ethylenically-unsaturated monomers. The polymer can be a branched
polymer or copolymer. For example, polymer can be a graft copolymer
having a polymeric backbone and a plurality of polymeric side
chains grafted to the polymeric backbone. In some cases, the
polymer can be a graft copolymer having a backbone of a first
chemical composition and a plurality of polymeric side chains that
are structurally distinct from the polymeric backbone (e.g., having
a different chemical composition than the polymeric backbone)
grafted to the polymeric backbone.
Examples of suitable ethylenically-unsaturated monomers include
(meth)acrylate monomers, vinyl aromatic monomers (e.g., styrene),
vinyl esters of a carboxylic acids, (meth)acrylonitriles, vinyl
halides, vinyl ethers, (meth)acrylamides and (meth)acrylamide
derivatives, ethylenically unsaturated aliphatic monomers (e.g.,
ethylene, butylene, butadiene), and combinations thereof. As used
herein, the term "(meth)acrylate monomer" includes acrylate,
methacrylate, diacrylate, and dimethacrylate monomers. Similarly,
the term "(meth)acrylonitrile" includes acrylonitrile,
methacrylonitrile, etc. and the term "(meth)acrylamide" includes
acrylamide, methacrylamide, etc.
Suitable (meth)acrylate monomers include esters of
.alpha.,.beta.-monoethylenically unsaturated monocarboxylic and
dicarboxylic acids having 3 to 6 carbon atoms with alkanols having
1 to 20 carbon atoms (e.g., esters of acrylic acid, methacrylic
acid, maleic acid, fumaric acid, or itaconic acid, with
C.sub.1-C.sub.20, C.sub.1-C.sub.12, C.sub.1-C.sub.8, or
C.sub.1-C.sub.4 alkanols). Exemplary (meth)acrylate monomers
include, but are not limited to, methyl acrylate, methyl
(meth)acrylate, ethyl acrylate, ethyl (meth)acrylate, butyl
acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, n-hexyl
(meth)acrylate, ethylhexyl (meth)acrylate, n-heptyl (meth)acrylate,
ethyl (meth)acrylate, 2-methylheptyl (meth)acrylate, octyl
(meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate,
isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl
(meth)acrylate, dodecyl (meth)acrylate, lauryl (meth)acrylate,
tridecyl (meth)acrylate, stearyl (meth)acrylate, glycidyl
(meth)acrylate, alkyl crotonates, vinyl acetate, di-n-butyl
maleate, di-octylmaleate, acetoacetoxyethyl (meth)acrylate,
acetoacetoxypropyl (meth)acrylate, hydroxyethyl (meth)acrylate,
allyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, cyclohexyl
(meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-methoxy
(meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate,
2-ethylhexyl (meth)acrylate, 2-propylheptyl (meth)acrylate,
2-phenoxyethyl (meth)acrylate, isobornyl (meth)acrylate,
caprolactone (meth)acrylate, polypropyleneglycol
mono(meth)acrylate, polyethyleneglycol (meth)acrylate, benzyl
(meth)acrylate, 2,3-di(acetoacetoxy)propyl (meth)acrylate,
hydroxypropyl (meth)acrylate, methylpolyglycol (meth)acrylate,
3,4-epoxycyclohexylmethyl (meth)acrylate, 1,6 hexanediol
di(meth)acrylate, 1,4 butanediol di(meth)acrylate and combinations
thereof.
Suitable vinyl aromatic compounds include styrene, .alpha.- and
p-methylstyrene, .alpha.-butylstyrene, 4-n-butylstyrene,
4-n-decylstyrene, vinyltoluene, and combinations thereof. Suitable
vinyl esters of carboxylic acids include vinyl esters of carboxylic
acids comprising up to 20 carbon atoms, such as vinyl laurate,
vinyl stearate, vinyl propionate, versatic acid vinyl esters, and
combinations thereof. Suitable vinyl halides can include
ethylenically unsaturated compounds substituted by chlorine,
fluorine or bromine, such as vinyl chloride and vinylidene
chloride. Suitable vinyl ethers can include, for example, vinyl
ethers of alcohols comprising 1 to 4 carbon atoms, such as vinyl
methyl ether or vinyl isobutyl ether. Aliphatic hydrocarbons having
2 to 8 carbon atoms and one or two double bonds can include, for
example, hydrocarbons having 2 to 8 carbon atoms and one olefinic
double bond, such as ethylene, as well as hydrocarbons having 4 to
8 carbon atoms and two olefinic double bonds, such as butadiene,
isoprene, and chloroprene.
In some embodiments, the polymer derived from one or more
ethylenically-unsaturated monomers comprises a copolymer of
ethylene and n-butyl acrylate. In some embodiments, the polymer
derived from one or more ethylenically-unsaturated monomers
comprises a copolymer of styrene and one or more of isoprene and
butadiene. In certain embodiments, the polymer derived from one or
more ethylenically-unsaturated monomers comprises a
metallocene-catalyzed polyolefin. Examples of suitable
metallocene-catalyzed polyolefins include metallocene polyethylene
homopolymers and metallocene polyethylene copolymers, which are
commercially available, for example, from Exxon Mobil Corporation
(under the trade name EXACT.RTM.) and Dow Chemical Company (under
the trade name AFFINITY.RTM.).
In certain embodiments, the polymer derived from one or more
ethylenically-unsaturated monomers comprises a polymer derived from
vinyl acetate. Polymers derived from vinyl acetate include polymers
derived, at least in part, from polymerization of vinyl acetate
monomers. For example, the polymer derived from vinyl acetate can
be a homopolymer of vinyl acetate (i.e., polyvinyl acetate; PVA).
The polymer derived from vinyl acetate can also be a copolymer of
vinyl acetate and one or more additional ethylenically-unsaturated
monomers (e.g., poly(ethylene-co-vinyl acetate), EVA). In these
embodiments, the polymer derived from vinyl acetate can be derived
from varying amounts of vinyl acetate, so as to provide a polymer
having the chemical and physical properties suitable for a
particular application.
In some embodiments, the polymer derived from vinyl acetate is
derived from at least 5% by weight vinyl acetate, based on the
total weight of all of the monomers polymerized to form the polymer
(e.g., at least 7.5% by weight, at least 9% by weight, at least 10%
by weight, at least 11% by weight, at least 12% by weight, at least
13% by weight, at least 14% by weight, at least 15% by weight, at
least 16% by weight, at least 17% by weight, at least 18% by
weight, at least 19% by weight, at least 20% by weight, at least
21% by weight, at least 22% by weight, at least 23% by weight, at
least 24% by weight, at least 25% by weight, at least 26% by
weight, at least 27% by weight, at least 28% by weight, at least
29% by weight, at least 30% by weight, at least 31% by weight, at
least 32% by weight, at least 33% by weight, at least 34% by
weight, at least 35% by weight, at least 37.5% by weight, at least
40% by weight, at least 45% by weight, at least 50% by weight, at
least 55% by weight, at least 60% by weight, at least 65% by
weight, at least 70% by weight, at least 75% by weight, at least
80% by weight, at least 85% by weight, or at least 90% by weight).
In some embodiments, the polymer derived from vinyl acetate is
derived from 95% by weight or less vinyl acetate, based on the
total weight of all of the monomers polymerized to form the polymer
(e.g., 90% by weight or less, 85% by weight or less, 80% by weight
or less, 75% by weight or less, 70% by weight or less, 65% by
weight or less, 60% by weight or less, 55% by weight or less, 50%
by weight or less, 45% by weight or less, 40% by weight or less,
37.5% by weight or less, 35% by weight or less, 34% by weight or
less, 33% by weight or less, 32% by weight or less, 31% by weight
or less, 30% by weight or less, 29% by weight or less, 28% by
weight or less, 27% by weight or less, 26% by weight or less, 25%
by weight or less, 24% by weight or less, 23% by weight or less,
22% by weight or less, 21% by weight or less, 20% by weight or
less, 19% by weight or less, 18% by weight or less, 17% by weight
or less, 16% by weight or less, 15% by weight or less, 14% by
weight or less, 13% by weight or less, 12% by weight or less, 11%
by weight or less, 10% by weight or less, 9% by weight or less, or
7.5% by weight or less).
The polymer derived from vinyl acetate can be a copolymer derived
from an amount of vinyl acetate ranging from any of the minimum
values above to any of the maximum values above. For example, the
polymer derived from vinyl acetate can be a copolymer derived from
5% by weight to less than 100% by weight vinyl acetate, based on
the total weight of all of the monomers polymerized to form the
polymer (e.g., from 5% by weight to 75% by weight vinyl acetate,
from 10% by weight to 40% by weight vinyl acetate, or from 17% by
weight to 34% by weight vinyl acetate).
In the case of copolymers derived from vinyl acetate and one or
more ethylenically-unsaturated monomers, any suitable
ethylenically-unsaturated monomers can be incorporated in the
copolymer, so as to provide a copolymer having the chemical and
physical properties desired for a particular application. By way of
example, suitable ethylenically-unsaturated monomers which can be
incorporated into the copolymers include those described above,
including (meth)acrylate monomers, vinyl aromatic monomers (e.g.,
styrene), vinyl esters of a carboxylic acids, (meth)acrylonitriles,
vinyl halides, vinyl ethers, (meth)acrylamides and (meth)acrylamide
derivatives, ethylenically unsaturated aliphatic monomers (e.g.,
ethylene, butylene, butadiene), and combinations thereof.
In certain embodiments, the polymer is poly(ethylene-co-vinyl
acetate) (EVA). EVA is a copolymer derived from ethylene and vinyl
acetate. EVA is widely used in a variety of applications, including
as a copolymer in hot-melt adhesives, in road marking and pavement
marking applications, in biomedical applications (e.g., as a matrix
for controlled drug delivery), as an additive in plastic films, and
as a foam in a variety of consumer products. Optionally, the EVA
copolymer can be grafted with suitable olefinic monomers, such as
butadiene, to obtain copolymers having the particular chemical and
physical properties required for a particular application. See, for
example, U.S. Pat. No. 3,959,410 to DiRossi and U.S. Pat. No.
5,036,129 to Atwell, et al.
In certain embodiments, the polymer is EVA derived from 9% by
weight to less than 45% by weight vinyl acetate, based on the total
weight of all of the monomers polymerized to form the polymer
(e.g., from 17% by weight to 40% by weight vinyl acetate, from 17%
by weight to 34% by weight vinyl acetate, or from 25% by weight to
30% by weight vinyl acetate) and from greater than 55% by weight to
91% by weight ethylene (e.g., from 60% by weight to 83% by weight
vinyl acetate, from 66% by weight to 83% by weight vinyl acetate,
or from 70% by weight to 75% by weight vinyl acetate). In one
embodiment, the polymer derived from vinyl acetate is EVA derived
from 26% by weight to 28% by weight vinyl acetate and from 72% by
weight to 74% by weight ethylene, based on the total weight of all
of the monomers polymerized to form the polymer.
In some embodiments, the polymer has a melting temperature, as
measured by differential scanning calorimetry (DSC) using the
standard method described in ISO 11357-3:2011, of greater than
25.degree. C. (e.g., greater than 30.degree. C., greater than
35.degree. C., greater than 40.degree. C., greater than 45.degree.
C., greater than 50.degree. C., greater than 55.degree. C., greater
than 60.degree. C., greater than 65.degree. C., greater than
70.degree. C., greater than 75.degree. C., greater than 80.degree.
C., or greater than 85.degree. C., greater than 90.degree. C., or
greater than 95.degree. C.). The polymer derived from vinyl acetate
can have a melting temperature of less than 100.degree. C. (e.g.,
less than 95.degree. C., less than 90.degree. C., less than
85.degree. C., less than 80.degree. C., less than 75.degree. C.,
less than 70.degree. C., less than 65.degree. C., less than
60.degree. C., less than 55.degree. C., less than 50.degree. C.,
less than 45.degree. C., less than 40.degree. C., less than
35.degree. C., or less than 30.degree. C.)
The polymer can have a melting temperature ranging from any of the
minimum values above to any of the maximum values above. For
example, the polymer can have a melting temperature, as measured by
differential scanning calorimetry (DSC) using the standard method
described in ISO 11357-3:2011, of from 25.degree. C. to 100.degree.
C. (e.g., from 25.degree. C. to 90.degree. C., from 35.degree. C.
to 85.degree. C., or 50.degree. C. to 80.degree. C.).
The rosin ester can be present in the polymeric compositions in
varying amounts, depending upon the desired properties of the
composition. In some embodiments, the rosin ester comprises at
least 5% by weight of the composition (e.g., at least 10% by weight
of the composition, at least 15% by weight of the composition, at
least 20% by weight of the composition, at least 25% by weight of
the composition, at least 30% by weight of the composition, at
least 35% by weight of the composition, at least 40% by weight of
the composition, or at least 45% by weight of the composition). In
some embodiments, the rosin ester comprises 50% or less of the
composition by weight (e.g., 45% or less by weight, 40% or less by
weight, 35% or less by weight, 30% or less by weight, 25% or less
by weight, 20% or less by weight, 15% or less by weight, or 10% or
less by weight). The rosin ester can be present in the composition
in an amount ranging from any of the minimum values above to any of
the maximum values above. In some embodiments, rosin ester is
present in the composition in an amount ranging from 20% to 50% by
weight, based on the total weight of the composition (e.g., from
30% to 40% by weight).
Similarly, the polymer derived from one or more
ethylenically-unsaturated monomers can be present in the polymeric
compositions in varying amounts, depending upon the desired
properties of the composition. In some embodiments, the polymer
derived from one or more ethylenically-unsaturated monomers
comprises at least 20% by weight of the composition (e.g., at least
25% by weight of the composition, at least 30% by weight of the
composition, at least 35% by weight of the composition, at least
40% by weight of the composition, at least 45% by weight of the
composition, at least 50% by weight of the composition, at least
55% by weight of the composition, at least 60% by weight of the
composition; at least 65% by weight of the composition, at least
70% by weight of the composition, at least 75% by weight of the
composition, at least 80% by weight of the composition, at least
85% by weight of the composition, or at least 90% by weight of the
composition). In some embodiments, the polymer derived from one or
more ethylenically-unsaturated monomers comprises 95% or less of
the composition by weight (e.g., 90% or less by weight, 85% or less
by weight, 80% or less by weight, 75% or less by weight, 70% or
less by weight, 65% or less by weight, 60% or less by weight, 55%
or less by weight, 50% or less by weight, 45% or less by weight,
40% or less by weight, 35% or less by weight, 30% or less by
weight, 25% or less by weight, 20% or less by weight, 15% or less
by weight, or 10% or less by weight). The rosin ester can be
present in the composition in an amount ranging from any of the
minimum values above to any of the maximum values above. In some
embodiments, the polymer derived from one or more
ethylenically-unsaturated monomers is present in the composition in
an amount ranging from 20% to 60% by weight, based on the total
weight of the composition (e.g., from 30% to 40% by weight).
In certain embodiments, the weight ratio of the polymer derived
from one or more ethylenically-unsaturated monomers to the total
amount of esterified dehydroabietic acid and esterified
dihydroabietic acid in the composition is at least 1:2.2 (e.g., at
least 1:2.1, at least 1:2.0, at least 1:1.9, at least 1:1.8, at
least 1:1.7, at least 1:1.6, at least 1:1.5, at least 1:1.4, at
least 1:1.3, at least 1:1.2, at least 1:1.1, at least 1:1, at least
1.1:1, at least 1.2:1, at least 1.3:1, at least 1.4:1, at least
1.5:1, at least 1.6:1, at least 1.7:1, at least 1.8:1, at least
1.9:1, at least 2:1, at least 2.1:1, at least 2.2:1, at least
2.3:1, at least 2.4:1, at least 2.5:1, at least 2.6:1, at least
2.7:1, at least 2.8:1, at least 2.9:1, at least 3:1, at least
3.1:1, at least 3.2:1, at least 3.3:1, at least 3.4:1, at least
3.5:1, at least 3.6:1, at least 3.7:1, at least 3.8:1, at least
3.9:1, at least 4:1, at least 4.1:1, or at least 4.2:1). In certain
embodiments, the weight ratio of the polymer derived from one or
more ethylenically-unsaturated monomers to the total amount of
esterified dehydroabietic acid and esterified dihydroabietic acid
in the composition is 4.3:1 or less (e.g., 4.2:1 or less, 4.1:1 or
less, 4:1 or less, 3.9:1 or less, 3.8:1 or less, 3.7:1 or less,
3.6:1 or less, 3.5:1 or less, 3.4:1 or less, 3.3:1 or less, 3.2:1
or less, 3.1:1 or less, 3:1 or less, 2.9:1 or less, 2.8:1 or less,
2.7:1 or less, 2.6:1 or less, 2.5:1 or less, 2.4:1 or less, 2.3:1
or less, 2.2:1 or less, 2.1:1 or less, 2:1 or less, 1.9:1 or less,
1.8:1 or less, 1.7:1 or less, 1.6:1 or less, 1.5:1 or less, 1.4:1
or less, 1.3:1 or less, 1.2:1 or less, 1.1:1 or less, 1:1 or less,
1:1.1 or less, 1:1.2 or less, 1:1.3 or less, 1:1.4 or less, 1:1.5
or less, 1:1.6 or less, 1:1.7 or less, 1:1.8 or less, 1:1.9 or
less, 1:2 or less, or 1:2.1 or less). The weight ratio of the
polymer derived from one or more ethylenically-unsaturated monomers
to the total amount of esterified dehydroabietic acid and
esterified dihydroabietic acid in the composition can range from
any of the minimum values above to any of the maximum values above.
For example, in some embodiments, the weight ratio of the polymer
derived from one or more ethylenically-unsaturated monomers to the
total amount of esterified dehydroabietic acid and esterified
dihydroabietic acid in the composition is from 1:2.2 to 4.3:1
(e.g., from 1:1.1 to 2:1).
In some cases, the polymeric composition can be an adhesive
formulation (e.g., hot-melt adhesive formulation), an ink
formulation, a coating formulation, a rubber formulation, a sealant
formulation, an asphalt formulation, or a pavement marking
formulation (e.g. a thermoplastic road marking formulation).
In certain embodiments, the composition is a hot-melt adhesive. In
these embodiments, the rosin ester can function as all or a portion
of the tackifier component in a traditional hot-melt adhesive
formulation. The polymer derived from one or more
ethylenically-unsaturated monomers (e.g., a polymer derived from
vinyl acetate such as EVA), the rosin ester, and one or more
additional components, can be present in amounts effective to
provide a hot-melt adhesive having the characteristics required for
a particular application. For example, the polymer derived from one
or more ethylenically-unsaturated monomers (e.g., a polymer derived
from vinyl acetate such as EVA), can be from 10% by weight to 60%
by weight of the hot-melt adhesive composition (e.g., from 20% by
weight to 60% by weight of the hot-melt adhesive composition, from
25% by weight to 50% by weight of the hot-melt adhesive
composition, or from 30% by weight to 40% by weight of the hot-melt
adhesive composition). The rosin ester can be from 20% by weight to
50% by weight of the hot-melt adhesive composition (e.g., from 25%
by weight to 45% by weight of the hot-melt adhesive composition, or
from 30% by weight to 40% by weight of the hot-melt adhesive
composition).
The hot-melt adhesive can further include one or more additional
components, including additional tackifiers, waxes, stabilizers
(e.g., antioxidants and UV stabilizers), plasticizers (e.g.,
benzoates and phthalates), paraffin oils, nucleating agents,
optical brighteners, pigments dyes, glitter, biocides, flame
retardants, anti-static agents, anti-slip agents, anti-blocking
agents, lubricants, and fillers. In some embodiments, the hot-melt
adhesive further comprises a wax. Suitable waxes include
paraffin-based waxes and synthetic Fischer-Tropsch waxes. The waxes
can be from 10% by weight to 40% by weight of the hot-melt adhesive
composition, based on the total weight of the composition (e.g.,
from 20% by weight to 30% by weight of the hot-melt adhesive
composition).
In certain embodiments, the composition is a hot-melt adhesive and
the polymer derived from one or more ethylenically-unsaturated
monomers is EVA. In certain embodiments, the EVA can be derived
from 10% by weight to 40% by weight vinyl acetate, based on the
total weight of all of the monomers polymerized to form the EVA
(e.g., from 17% by weight to 34% by weight vinyl acetate).
In certain embodiments, the composition is a thermoplastic road
marking formulation. The thermoplastic road marking formulation can
include from 5% by weight to 25% by weight of a rosin ester, based
on the total weight of the thermoplastic road marking formulation
(e.g., from 10% by weight to 20% by weight of the thermoplastic
road marking formulation). The thermoplastic road marking
formulation can further include a polymer derived from one or more
ethylenically-unsaturated monomers (e.g., a polymer derived from
vinyl acetate such as EVA) which can be, for example, from 0.1% by
weight to 1.5% by weight of the thermoplastic road marking
formulation. The thermoplastic road marking formulation can further
include a pigment (e.g., from 1% by weight to 10% by weight
titanium dioxide), and glass beads (e.g., from 30% by weight to 40%
by weight), and a filler calcium carbonate which can make up the
balance of the composition up to 100% by weight). The thermoplastic
road marking formulation can further include an oil (e.g., from 1%
by weight to 5% by weight percent mineral oil), a wax (e.g., from
1% by weight to 5% by weight percent paraffin-based wax or
synthetic Fischer-Tropsch wax), a stabilizer (e.g., from 0.1% by
weight to 0.5% by weight stearic acid), and, optionally, additional
polymers and/or binders other than the rosin ester described
herein.
In some embodiments, by incorporating a rosin ester described
herein into the polymeric composition, the polymeric composition
can exhibit improved thermal stability, including improved
viscosity stability on aging at elevated temperatures (thermal
aging), improved color stability on thermal aging, or combinations
thereof.
In some embodiments, the polymeric compositions provided herein
exhibit less than a 10% change in viscosity upon incubation at
177.degree. C. for 96 hours, when analyzed using the modified ASTM
D4499-07 method described below (e.g., less than a 9% change in
viscosity, less than an 8% change in viscosity, less than a 7.5%
change in viscosity, less than a 7% change in viscosity, less than
a 6% change in viscosity, less than a 5% change in viscosity, less
than a 4% change in viscosity, less than a 3% change in viscosity,
less than a 2.5% change in viscosity, less than a 2% change in
viscosity, or less than a 1% change in viscosity). In some
embodiments, the composition exhibits substantially no change in
viscosity (i.e., less than a 0.5% change in viscosity) upon
incubation at 177.degree. C. for 96 hours.
In some embodiments, the polymeric compositions provided herein
exhibit color stability upon thermal aging. In certain cases, the
polymeric compositions provided herein exhibit a change of 5 or
less Gardner color units when heated to a temperature of
177.degree. C. for a period of 96 hours (e.g., 4.5 or less, 4.0 or
less, 3.5 or less, 3.0 or less, 2.5 or less, 2.0 or less, 1.5 or
less, 1.0 or less, or 0.5 or less).
The polymeric compositions provided herein can be used in a variety
of applications, including as adhesives (e.g., hot-melt adhesives),
inks, coatings, rubbers, sealants, asphalt, and thermoplastic road
markings and pavement markings. In some embodiments, the
compositions are hot-melt adhesives used, for example, in
conjunction with papers and packaging (e.g., to adhere surfaces of
corrugated fiberboard boxes and paperboard cartons during assembly
and/or packaging, to prepare self-adhesive labels, to apply labels
to packaging, or in other applications such as bookbinding), in
conjunction with non-woven materials (e.g., to adhere nonwoven
material with a backsheet during the construction of disposable
diapers), in adhesive tapes, in apparel (e.g., in the assembly of
footware, or in the assembly of multi-wall and specialty handbags),
in electrical and electronic bonding (e.g., to affix parts or wires
in electronic devices), in general wood assembly (e.g., in
furniture assembly, or in the assembly of doors and mill work), and
in other industrial assembly (e.g., in the assembly of appliances).
The rosin esters described herein can also be used in a variety of
additional applications, including as a softener and plasticizer in
chewing gum bases, as a weighting and clouding agent in beverages
(e.g., citrus flavored beverages), as a surfactant, surface
activity modulator, or dispersing agent, as an additive in waxes
and wax-based polishes, as a modifier in cosmetic formulations
(e.g., mascara), and as a curing agent in concrete.
Also provided are compositions comprising a rosin ester described
herein and an oil. Exemplary compositions can include 25% by weight
to 55% by weight (e.g., 30% by weight to 50% by weight) of a rosin
ester described herein and 45% by weight to 75% by weight (e.g.,
50% by weight to 70% by weight) of an oil, such as mineral oil or
poly-butene oil.
Also provided are methods of making the rosin esters described
herein. Methods of making rosin esters can comprise (a) esterifying
a rosin with an alcohol to provide a crude rosin ester composition,
and (b) hydrogenating the crude rosin ester composition to form the
rosin ester.
Esterification step (a) can comprise contacting a rosin with a
suitable alcohol, and allowing the rosin and the alcohol to react
for a period of time and under suitable conditions to form the
crude rosin ester. Methods of esterifying rosin are known in the
art. See, for example, U.S. Pat. No. 5,504,152 to Douglas et al.,
which is hereby incorporated by reference in its entirety. Suitable
methods for esterifying rosin can be selected in view of a number
of factors, including the nature of the reactants (e.g., the
chemical and physical properties of the rosin, the identity of the
alcohol, etc.) and the desired chemical and physical properties of
the resultant rosin ester. For example, rosin can be esterified by
a thermal reaction of the rosin with an alcohol. Esterification can
comprise contacting the rosin with the alcohol at an elevated
temperature (e.g., at a temperature from greater than greater than
30.degree. C. to 250.degree. C.). In some embodiments,
esterification step (a) can involve contacting molten rosin with an
alcohol and optionally an esterification catalyst for a period of
time suitable to form the crude rosin ester. In some cases, the
esterification reaction involves contacting the rosin with an
alcohol and optionally an esterification catalyst for a period of
time effective to provide a rosin ester having an acid number of 15
or less.
Any suitable rosin can be used in esterification step (a). The
rosin can be a tall oil rosin, a gum rosin, a wood rosin, or a
combinations thereof. In certain embodiments, the rosin comprises
tall oil rosin. Rosins can be used as a feedstock for the formation
of rosin esters as obtained from a commercial or natural source.
Examples of commercially available rosins include tall oil rosins
such as SYLVAROS.RTM. 90, commercially available from Arizona
Chemical. Alternatively, rosin can be subjected to one or more
purification steps (e.g., distillation under reduced pressure,
extraction, and/or crystallization) prior to its use as a feedstock
for the formation of rosin esters.
Any suitable alcohol, include monoalcohols, diols, and other
polyols, can be used in esterification step (a). Examples of
suitable alcohols include glycerol, pentaerythritol,
dipentaerythritol, ethylene glycol, diethylene glycol, triethylene
glycol, sorbitol, neopentylglycol, trimethylolpropane, methanol,
ethanol, propanol, butanol, amyl alcohol, 2-ethyl hexanol,
diglycerol, tripentaerythritol, C.sub.8-C.sub.11 branched or
unbranched alkyl alcohols, and C.sub.7-C.sub.16 branched or
unbranched arylalkylalcohols. In certain embodiments, the alcohol
is a polyhydric alcohol selected from the group consisting of
ethylene glycol, propylene glycol, diethylene glycol, triethylene
glycol, tetraethylene glycol, trimethylene glycol, glycerol,
trimethylolpropane, trimethylolethane, pentaerythritol, mannitol,
and combinations thereof. In some embodiments, more than one
alcohol is used in esterification step (a). In certain embodiments,
pentaerythritol and one or more additional alcohols selected from
the group consisting of glycerol, dipentaerythritol, ethylene
glycol, diethylene glycol, triethylene glycol, trimethylolpropane,
and combinations thereof are used in esterification step (a).
The amount of alcohol employed in esterification step (a) relative
to the amount of rosin can be varied, depending on the nature of
the alcohol and the desired chemical and physical properties of the
resultant rosin ester. In some embodiments, the rosin is provided
in excess so as to produce a resultant rosin ester having a low
hydroxyl number. For example, the alcohol can be provided in an
amount such that less than a molar equivalent of hydroxy groups is
present in the reaction relative to the amount of rosin present. In
other embodiments, the alcohol is provided in excess so as to
produce a resultant rosin ester having a low acid number.
As is known in the art, catalysts, solvents, bleaching agents,
stabilizers, and/or antioxidants can be added in esterification
step (a). Suitable catalysts, solvents, bleaching agents,
stabilizers, and antioxidants are known in the art, and described,
for example, in U.S. Pat. Nos. 2,729,660, 3,310,575, 3,423,389,
3,780,013, 4,172,070, 4,548,746, 4,690,783, 4,693,847, 4,725,384,
4,744,925, 4,788,009, 5,021,548, and 5,049,652. In order to drive
the esterification reaction to completion, water can be removed
from the reactor using standard methods, such as distillation
and/or application of a vacuum.
Hydrogenation step (b) can comprise contacting the crude rosin
ester with a hydrogenation catalyst. Methods of hydrogenating rosin
esters are known in the art. Hydrogenation reactions can be carried
out using a catalyst, such as a heterogeneous hydrogenation
catalyst (e.g., a palladium catalyst, such as Pd supported on
carbon (Pd/C), a platinum catalyst, such as PtO.sub.2, a nickel
catalyst, such as Raney Nickel (Ra--Ni), a rhodium catalyst, or a
ruthenium catalyst). In some cases, the hydrogenation catalyst can
be present in an amount ranging from 0.25% to 5% by weight, based
on the total weight of the crude rosin ester. The hydrogen source
for the hydrogenation can by hydrogen (H.sub.2) or a compound which
can generate hydrogen under reaction conditions, such as formic
acid, isopropanol, cyclohexene, cyclohexadiene, a diimide, or
hydrazine.
Step (b) can be performed at an elevated temperature, an elevated
pressure, or combinations thereof. For example, step (b) is
performed at a temperature ranging from 150.degree. C. to
300.degree. C. (e.g., from 180.degree. C. to 280.degree. C., from
180.degree. C. to 240.degree. C., from 200.degree. C. to
280.degree. C. or from 220.degree. C. to 260.degree. C.). Step (b)
can performed at a pressure ranging from 250 to 2000 psi (e.g.,
from 250 to 1450 psi, from 250 to 650 psi, or from 350 to 550
psi).
Optionally a solvent can be present in esterification step (a),
hydrogenation step (b), or combinations thereof. In certain
embodiments, the rosin esterified in step (a) and/or the crude
rosin ester composition hydrogenated in step (b) comprise less than
25% by weight solvent. In some embodiments, the concentration of
esterified rosin acids in the crude rosin ester composition
hydrogenated in step (b) is 75% or more by weight, based on the
total weight of the crude rosin ester composition. In some
embodiments, the crude rosin ester composition is substantially
free of solvent (e.g., the crude rosin ester composition comprises
less than by weight solvent, based on the total weight of the crude
rosin ester composition). In certain embodiments, the crude rosin
ester composition hydrogenated in step (h) has a viscosity of 1,000
cP or less at 25.degree. C.
In some embodiments, the crude rosin ester composition obtained
from esterification step (a) is hydrogenated in step (b) without an
intervening distillation step. In certain embodiments, the crude
rosin ester composition obtained from esterification hydrogenated
in step (b) without any intervening purification step. For example,
the crude rosin ester composition obtained from esterification step
(a) can be directly hydrogenated in step (b).
In some cases, methods of making the rosin esters described herein
include only a single hydrogenation step. In some embodiments,
methods of making the rosin esters described herein consist
essentially of esterifying step (a) and hydrogenating step (b). In
such cases, the methods involve no additional processing steps
which influence the weight ratio of esterified dehydroabietic acid
to esterified dihydroabietic acid in the rosin ester, such as
dehydrogenation, hydrogenation of the rosin prior to esterification
(i.e., pre-hydrogenation), disproportionation of the rosin prior to
esterification (i.e., pre-disproportionation), distillation, the
use of additional/alternative catalysts, or combinations thereof.
In certain embodiments, methods of making the rosin esters
described herein consist of esterifying step (a) and hydrogenating
step (b).
To obtain a rosin ester having the desired chemical and physical
properties for particular applications, methods of making the rosin
esters described herein can optionally further include one or more
additional processing steps in addition to esterifying step (a) and
hydrogenating step (b). In some embodiments, the rosin to be
esterified in step (a), the crude rosin ester, and/or the rosin
ester can be further processed, for example, to decrease the PAN
number of the rosin, crude rosin ester, and/or rosin ester; to
influence the weight ratio of various rosin acids and/or rosin acid
esters present in the rosin, crude rosin ester, and/or rosin ester;
to influence the hydroxyl number of the resultant rosin ester; to
influence the acid number of the resultant rosin ester; or
combinations thereof. Suitable additional processing steps are
known in the art, and can include additional hydrogenation steps,
dehydrogenation, disproportionation, dimerization, and
fortification. In certain embodiments, rosin is processed using one
or more of these methods prior to esterifying step (a) to improve
the chemical and physical properties of the resultant rosin esters.
Where chemically permissible, such methods can also be performed in
combination with esterifying step (a), following esterifying step
(a) but prior to hydrogenating step (b), following hydrogenating
step (b), or combinations thereof to obtain a rosin ester having
the desired chemical and physical properties, as discussed in more
detail below.
In certain embodiments, the methods of making rosin esters can
further comprise disproportionating the rosin prior to the
esterifying step (a). Rosin disproportionation converts
abietadienoic acid moieties into dehydroabietic acid and
dihydroabietic acid moieties. Methods of disproportionation are
known in the art, and can involve heating rosin, often in the
presence of one or more disproportionation agents. Suitable methods
for disproportionating rosin are described in, for example, U.S.
Pat. Nos. 3,423,389, 4,302,371, and 4,657,703, all of which are
incorporated herein by reference.
A variety of suitable disproportionation agents can be used.
Examples of suitable disproportionation agents include
thiobisnaphthols, including 2,2'thiobisphenols,
3,3'-thiobisphenols, 4,4'-thiobis(resorcinol) and
t,t'-thiobis(pyrogallol), 4,4'-15 thiobis(6-t-butyl-m-cresol) and
4/4'-thiobis(6-t-butyl-o-cresol) thiobisnaphthols,
2,2'-thio-bisphenols, 3,3'-thio-bis phenols; metals, including
palladium, nickel, and platinum; iodine or iodides (e.g., iron
iodide); sulfides (e.g., iron sulfide); and combinations thereof.
In certain embodiments, the rosin is disproportionate using a
phenol sulfide type disproportionation agent. Examples of suitable
phenol sulfide type disproportionation agents include
poly-t-butylphenoldisulfide (commercially available under the trade
name ROSINOX.RTM. from Arkema, Inc.),
4,4'thiobis(2-t-butyl-5-methylphenol (commercially available under
the trade name LOWINOX.RTM. TBM-6 from Chemtura), nonylphenol
disulfide oligomers (such as those commercially available under the
trade name ETHANOX.RTM. TM323 from Albemarle Corp.), and amylphenol
disulfide polymer (such as those commercially available under the
trade name VULTAC.RTM. 2 from Sovereign Chemical Co.).
In certain embodiments, the rosin is disproportionated prior to
esterifying step (a). In these embodiments, a disproportionated
rosin or partly disproportionated rosin can be used as a feedstock
for esterifying step (a). In some cases, disproportionation or
further disproportionation can be conducted during esterifying step
(a). For example, disproportionated or partly disproportionated
rosin can be generated in situ and esterified thereafter in a
one-pot synthesis procedure to a rosin ester.
Optionally, the rosin, crude rosin ester, and/or rosin ester can be
fortified to improve the chemical and physical properties of the
resultant rosin esters. In some embodiments, rosin is fortified
prior to esterifying step (a) to improve the chemical and physical
properties of the resultant rosin esters. Fortification of rosin
involves the chemical modification of the conjugated double bond
system of rosin acids in the rosin, so as to provide a rosin having
a lower PAN number and higher molecular weight than the rosin prior
to fortification. A number of suitable chemical modifications and
related chemical methods are known in the art. For example, rosins
can be fortified by means of a Diels-Alder or Ene addition reaction
of a rosin acid with a dienophile, such as an
.alpha.,.beta.-unsaturated organic acid or the anhydride of such an
acid. Examples of suitable dienophiles include maleic acid, fumaric
acid, acrylic acid, esters derived from these acids, and maleic
anhydride.
Optionally, methods can include one or more process steps to
influence the hydroxyl number of the resultant rosin ester, to
influence the acid number of the resultant rosin ester; or
combinations thereof. If desired, rosin esters can be chemically
modified following esterification (e.g., following esterifying step
(a) but prior to hydrogenating step (b) or following hydrogenating
step (b)) to provide a rosin ester having a low hydroxyl number.
This process can involve chemical modification of residual hydroxyl
moieties in the crude rosin ester or rosin esters following
esterification using synthetic methods known in the art. For
example, the crude rosin ester or rosin ester can be reacted with
an acylating agent (e.g., a carboxylic acid or a derivative
thereof, such as an acid anhydride). See, for example, U.S. Pat.
No. 4,380,513 to Ruckel. Residual hydroxyl moieties in the crude
rosin ester or rosin ester can also be reacted with an
electrophilic reagent, such as an isocyanate, to produce the
corresponding carbamate derivative. See, for example, U.S. Pat. No.
4,377,510 to Ruckel. Other suitable electrophilic reagents which
can be used to react residual hydroxyl moieties include alkylating
agents (e.g., methylating agents such as dimethylsulphate). If
desired, following esterification (e.g., following esterifying step
(a) but prior to hydrogenating step (b) or following hydrogenating
step (b)), unreacted rosin as well as other volatile components,
can be removed from the crude rosin ester or rosin ester, for
example, by steam sparging, sparging by an inert gas such as
nitrogen gas, wiped film evaporation, short path evaporation, and
vacuum distillation. By stripping excess rosin (i.e., rosin acids)
from the crude rosin ester or rosin ester, the acid number of the
resultant rosin ester can be reduced.
Also provided are methods for preparing polymer compositions,
including hot-melt adhesives. Methods for preparing polymer
compositions can include mixing a polymer derived from vinyl
acetate and a rosin ester as described herein (e.g., a rosin ester
comprising at least 70% by weight of an esterified dehydroabietic
acid and an esterified dihydroabietic acid, wherein the weight
ratio of the esterified dehydroabietic acid to the esterified
dihydroabietic acid ranges from 1.3:1 to 1:2.6). Methods can
further include adding one or more additional components to the
composition, such as an additional tackifier, a wax, a stabilizer
(e.g., an antioxidant UV stabilizer), a plasticizer (e.g.,
benzoates, phthalates), paraffin oil, a nucleating agent, an
optical brightener, a pigment, a dye, glitter, a biocide, a flame
retardant, an anti-static agent, an anti-slip agent, an
anti-blocking agent, a lubricants, a filler, or a combination
thereof. Methods can further include preparing a rosin ester (e.g.,
a rosin ester comprising at least 70% by weight of an esterified
dehydroabietic acid and an esterified dihydroabietic acid, wherein
the weight ratio of the esterified dehydroabietic acid to the
esterified dihydroabietic acid ranges from 1.3:1 to 1:2.6) using
the methods described herein.
An exemplary road marking formulation may be prepared by: (a)
charging a standard mixer with 16 parts rosin ester, 2.8 parts oil
(e.g., a mineral oil, such as mineral oil; obtained from Statoil),
1 part wax (e.g., polyethylene wax, such as AC6 PE-wax obtained
from Honeywell), 1 part of a polymer derived from vinyl acetate
(e.g., poly(ethylene-co-vinyl acetate) such as Elvax 22W obtained
from DuPont), 0.2 parts fatty acid (e.g., stearic acid), 5.3 parts
pigment (e.g., titanium dioxide, such as titanium dioxide obtained
from Kronos), 42.4 parts filler (e.g., calcium carbonate), and 37.1
parts reflective filler (e.g., glass beads, such as glass beads
obtained from Swarco); and (b) heating (e.g., at 180.degree. C.)
and blending at low speed to avoid introducing air bubbles into the
melt.
By way of non-limiting illustration, examples of certain
embodiments of the present disclosure are included below.
EXAMPLES
General Methods
All materials were characterized using the following methods unless
otherwise stated. Hydroxyl numbers were determined according to a
modified method (different solvent tetrahydrofuran was applied) of
DIN 53240-2 entitled "Determination of Hydroxyl Value--Part 2:
Method with Catalyst," which is incorporated herein by reference in
its entirety. The rosin ester (dissolved in tetrahydrofuran) was
reacted with acetic anhydride in the presence of
4-dimethylaminopyridine (DMAP). Residual acetic anhydride was
hydrolyzed and the resulting mixture titrated with an alcoholic
solution of potassium hydroxide (0.5 M). The hydroxyl number is
expressed as mg KOH per gram rosin ester sample. Acid numbers were
determined according to method described in ASTM D465-05 (2010)
entitled "Standard Test Methods for Acid Number of Naval Stores
Products Including Tall Oil and Other Related Products," which is
incorporated herein by reference in its entirety. The acid number
is expressed as mg KOH per gram rosin ester sample. Softening
points were determined according to method described in ASTM E28-99
(2009) entitled "Standard Test Methods for Softening Point of
Resins Derived from Naval Stores by Ring-and-Ball Apparatus," which
is incorporated herein by reference in its entirety. The Gardner
color of all materials was measured according to the Gardner Color
scale as specified in ASTM D1544-04 (2010) entitled "Standard Test
Method for Color of Transparent Liquids (Gardner Color Scale),"
which is incorporated herein by reference in its entirety. Gardner
colors were measured using a Dr Lange LICO.RTM. 200 colorimeter.
Unless otherwise indicated, all Gardner colors were measured using
neat samples. Oxidative-induction time was measured according to
the standard methods specified in ASTM D5483-05(2010) entitled
"Standard Test Method for Oxidation Induction Time of Lubricating
Greases by Pressure Differential Scanning Calorimetry," which is
incorporated herein by reference in its entirety. Unless otherwise
specified, the oxidative-induction time was measured at 130.degree.
C. using 550 psi of oxygen. Sulfur content was measured according
to the standard methods described in ASTM D5453-05 entitled
"Standard Test Method for Determination of Total Sulfur in Light
Hydrocarbons, Motor Fuels and Oils by Ultraviolet Fluorescence,"
which is incorporated herein by reference in its entirety. Sulfur
content was measured using an ANTEK.RTM. 9000 sulfur analyzer.
The isomeric composition of the rosin esters, including the PAN
number and the ratio of esterified dehydroabietic acid to
esterified dihydroabietic acid, was determined according to the
methods described in ASTM D5974-00 (2010) entitled "Standard Test
Methods for Fatty and Rosin Acids in Tall Oil Fractionation
Products by Capillary Gas Chromatography," which is incorporated
herein by reference in its entirety. Specifically, a rosin ester
sample (1.00 g) and 10 mL 2N potassium hydroxide (KOH) in ethanol
were added to a high pressure microwave reaction vessel. The
reaction vessel was sealed and placed into the rotor of a Perkin
Elmer MULTIWAVE.RTM. 3000 Microwave System. The sample was
saponified in the microwave for 30 minutes at 150.degree. C. Upon
completion of the microwave-assisted saponification, the reaction
mixture was transferred to a separatory funnel, and dilute
hydrochloric acid was added to reduce the pH value to less than 4.
This converted the rosin soaps in the reaction mixture to rosin
acids. The resulting rosin acids were isolated by way of ethyl
ether extraction. Upon removal of the ether solvent, the rosin
acids were derivatized and analyzed using a gas chromatograph
according to ASTM D5974-00 (2010).
Preparation of Rosin Esters
Example 1
500 g of tall oil rosin (SYLVAROS.RTM. HYR, commercially available
from Arizona Chemical) with a Gardner color (neat) of 5.5 and an
acid number of 180.7 was charged into a four-necked flask (2 L) and
heated to 200.degree. C. under a nitrogen atmosphere. After the
rosin was completely melted, the rosin was agitated, and
pentaerythritol (57.4 g) and IRGANOX.RTM. 1425 (1.98 g) were added.
The reaction mixture was heated to 275.degree. C. (heating rate of
30.degree. C./hour) and left at this temperature for 7.5 hours. The
crude rosin ester was discharged, and analyzed to have a with a
Gardner color (neat) of 5.6, an acid number of 13.8, softening
point of 97.1.degree. C., and an oxidative-induction time of 0.5
minutes.
Without further purification, the crude rosin ester was
hydrogenated for 6 hours at 650 psi and 260.degree. C. using 2% by
weight palladium on carbon (5% Pd by weight). The catalyst was then
removed by filtration, providing a rosin ester with a Gardner color
(neat) of 1.4, an acid number of 11.2, softening point of
98.0.degree. C., and an oxidative-induction time of 39.6 minutes.
The color stability of the rosin ester was also tested. After
incubation for three hours at 160.degree. C., the rosin ester
exhibited a Gardner color (neat) of 1.4. The weight ratio of
esterified dehydroabietic acid to esterified dihydroabietic acid in
the resulting rosin ester was determined to be 1:1.6.
Example 2
The procedure of Example 1 was repeated, except that a solvent was
added during the hydrogenation reaction.
The crude rosin ester was prepared as described in Example 1.
Without further purification, the crude rosin ester was
hydrogenated for 6 hours at 650 psi and 260.degree. C. using 2% by
weight palladium on carbon (5% Pd by weight) in a 50% by weight
solution of dimethylcyclohexane. The catalyst was then removed by
filtration, and the solvent was removed by distillation. The
resulting rosin ester exhibited a Gardner color (neat) of 0.8, an
acid number of 11.4, softening point of 97.4.degree. C., a PAN
number of 0, and an oxidative-induction time of 43.0 minutes. The
color stability of the rosin ester was also tested. After
incubation for three hours at 160.degree. C., the rosin ester
exhibited a Gardner color (neat) of 0.8. The weight ratio of
esterified dehydroabietic acid to esterified dihydroabietic acid in
the resulting rosin ester was determined to be 1:1.6.
Example 3
500 g of tall oil rosin was charged into a four-necked flask (1 L).
The flask was placed under vacuum for 10-15 minutes. The vacuum was
then broken with nitrogen, and the flask was heated to 180.degree.
C. and agitated. ROSINOX.RTM. (poly-t-butylphenoldisulfide 1.74 g,
0.31 wt %, commercially available from Arkema, Inc) was added to
the reaction flask. The reaction flask contents were then stirred
for 5-10 minutes. A catalyst
(calcium-bis(((3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl)methyl-
)-ethylphosphonate), 1.98 g) and pentaerytritol (57.4 g) were
added, and the reaction was heated to 270.degree. C. at a rate of
35.degree. C. per hour. The reaction temperature was maintained at
275.degree. C. until the acid number of the mixture was less than
15. The crude rosin ester was discharged.
Without further purification the crude rosin ester was hydrogenated
for 6 hours at 450 psi and 260.degree. C. using 1.5% by weight
palladium on carbon (5% Pd by weight). The catalyst was then
removed by filtration in toluene, and the solvent was removed by
distillation. The resulting rosin ester exhibited a Gardner color
(neat) of 2.3, an acid number of 10, softening point of 96.degree.
C., and an oxidative-induction time of 44.4 minutes. The weight
ratio of esterified dehydroabietic acid to esterified
dihydroabietic acid in the resulting rosin ester was determined to
be 1.01:1.
Formulation of Hot-Melt Adhesives
Hot-melt adhesives were formulated using the rosin esters prepared
in Examples 1 and 2. The hot-melt adhesive compositions were
prepared by blending 20 wt % ESCORENE.RTM. Ultra UL 7711 EVA (EVA
copolymer with a 26.7 wt % vinyl acetate content, commercially
available from Exxon Mobil Chemical), 16.4 wt % ELVAX.RTM. EVA (EVA
copolymer with a 28 wt % vinyl acetate content, commercially
available from DuPont), 25 wt % SASOLWAX.RTM. H1 (unmodified
Fischer-Tropsch was commercially available from Sasolwax), 38 wt %
tackifier (rosin ester), and 0.6% ANOX.RTM. 20
(3,5-bis(1,1-dimethylethyl)-4-hydroxy-benzenepropanoic acid,
sterically hindered phenolic antioxidant commercially available
from Gulf Stabilizers Industries). For comparison, hot melt
adhesives were also prepared using SYLVAPACK.RTM. RE 100RC (tall
oil rosin ester with a Gardner color (neat) of 4, an acid number of
11, softening point of 93-100.degree. C., and a weight ratio of
esterified dehydroabietic acid to esterified dihydroabietic acid of
1:0.4; commercially available from Arizona Chemical) and
SYLVALITE.RTM. RE 105XL (tall oil rosin ester with a Gardner color
(neat) of 4, an acid number of 2, softening point of 102.degree.
C., and a weight ratio of esterified dehydroabietic acid to
esterified dihydroabietic acid in the resulting rosin ester was
determined to be 1:0.3; commercially available from Arizona
Chemical).
The thermal stability of the hot-melt adhesive formulations was
measured using a thermal stability test adapted from the test
methods described in ASTM D4499-07, entitled "Standard Test Method
for Heat Stability of Hot-Melt Adhesives," which is incorporated by
reference in its entirety. The viscosity of the hot-melt adhesives
was measured using a Brookfield viscometer equipped with a #27
spindle at 133.degree. C. and 177.degree. C. The viscosity is
measured in centipoise (cP).
The viscosity of each composition was measured at 0 hours, 48
hours, and 96 hours. The neat Gardner color of each composition was
also measured at 0 hours, 24 hours, 48 hours, 72 hours, and 96
hours. The results are shown in Table 1 below.
TABLE-US-00001 TABLE 1 Performance of Hot-Melt Adhesive
Formulations Containing Rosin Esters Time Garnder Viscosity .DELTA.
Tackifer (hours) Color (neat) .DELTA. Color.sup.1 (cP).sup.2
Viscosity.sup.3 Example 1 0 1.5 985 24 3 48 4 992 72 5 96 6.5 5
1008 2.3% Example 2 0 1.5 1025 24 2 48 3.5 1010 72 4.5 96 5.5 4
1020 0.5% RE 100RC 0 3.5 1082 24 5 48 5.5 1092 72 N/A 96 8 4.5 1258
16.0% RE 105XL 0 2.5 1092 24 4.5 48 6 952 72 N/A 96 9.5 7 998 8.6%
.sup.1.DELTA. Color denotes the difference between the intial
Gardner color of the composition (measured at 0 hours) and the
final Gardner color of the composition (measured at 96 hours)
measured according to the method described in ASTM D1544-04 (2010).
.sup.2Viscosity measured at 177.degree. C. using a Brookfield
viscometer equipped with a #27 spindle .sup.3.DELTA. Viscosity
denotes the percent difference between the initial viscosity of the
composition (measured at 0 hours) and the final viscosity of the
composition (measured at 96 hours) measured according to the method
described in ASTM 4499-07.
The compositions and methods of the appended claims are not limited
in scope by the specific compositions and methods described herein,
which are intended as illustrations of a few aspects of the claims.
Any compositions and methods that are functionally equivalent are
intended to fall within the scope of the claims. Various
modifications of the compositions and methods in addition to those
shown and described herein are intended to fall within the scope of
the appended claims. Further, while only certain representative
compositions and method steps disclosed herein are specifically
described, other combinations of the compositions and method steps
also are intended to fall within the scope of the appended claims,
even if not specifically recited. Thus, a combination of steps,
elements, components, or constituents may be explicitly mentioned
herein or less, however, other combinations of steps, elements,
components, and constituents are included, even though not
explicitly stated.
The term "comprising" and variations thereof as used herein is used
synonymously with the term "including" and variations thereof and
are open, non-limiting terms. Although the terms "comprising" and
"including" have been used herein to describe various embodiments,
the terms "consisting essentially of" and "consisting of" can be
used in place of "comprising" and "including" to provide for more
specific embodiments of the invention and are also disclosed. Other
than where noted, all numbers expressing geometries, dimensions,
and so forth used in the specification and claims are to be
understood at the very least, and not as an attempt to limit the
application of the doctrine of equivalents to the scope of the
claims, to be construed in light of the number of significant
digits and ordinary rounding approaches.
Unless defined otherwise, all technical and scientific terms used
herein have the same meanings as commonly understood by one of
skill in the art to which the disclosed invention belongs.
Publications cited herein and the materials for which they are
cited are specifically incorporated by reference.
* * * * *